Biological and drug samples are often stored and/or transported for lengthy periods of time before use. To maintain the viability of such samples, the storage or transport units are typically configured with refrigeration systems or coolants that maintain an interior storage space at a desired temperature, typically a low or cryogenic temperature such as within a range of about −195° C. to about −40° C. The specific temperature depends on the samples being stored. In one example, stem cells to be used for research tests and activities are typically stored at about −195° C. to maintain the viability thereof. Allogeneic and autologous drug products may also be stored at similar temperatures, for example. As will be readily understood, any prolonged exposure of such samples to higher temperatures such as room temperatures can cause temperature-induced degradation that may ruin the samples. Therefore, it is important to store and handle these biological and drug samples in such a manner to avoid those temperature-induced degradations.
Storage of samples in cryogenic containers is typically done with one or more storage racks that hold and organize a plurality of samples. One conventional example of such a storage rack 300 is shown in FIG. 1. The storage rack 300 defines a rectangular box shape or cross section formed by a plurality of elongated side walls 302 and an open front surface, with a plurality of shelves 304 provided along the length of the side walls 302. The remainder of the rectangular box shape is generally solid, although there may be air flow apertures formed along the side walls 302 as well, to promote cold air flow through the storage spaces defined at the shelves 304. The storage spaces are sized to receive one or more sample storage boxes 306, which also define a generally rectangular cross section. The storage rack 300 of the conventional design further includes a small clip 308 along a top wall 310 which serves as a handle for moving the storage rack 300, and a retainer bar 312 that extends through apertures formed in the top wall 310 and in each of the plurality of shelves 304 along the open front surface to block the storage boxes 306 from falling out of the storage spaces. The storage rack 300 is typically received in a cylindrical storage sleeve 314 during storage in a cryogenic container, these elements being shown separated from one another in FIG. 1.
Although the storage rack 300 of the conventional design functions to organize and retain a number of product samples, the use and retrieval of product samples from the storage rack 300 often requires significant previous experience in order to perform these operations quickly. To this end, accessing one of the storage boxes 306 and the product sample(s) therein is a multi-step, relatively complicated process. More specifically, the storage rack 300 must first be pulled out of the storage sleeve 314, and this requires interaction with the small clip 308 that serves as a handle for the storage rack 300. It can be highly difficult to maintain a good grip on this clip 308 when moving the storage rack 300, as a result of its small size and low profile relative to the top wall 310. Next, a user must withdraw the retainer bar 312 by pulling it upwardly out of all of the apertures provided in the shelves 304 and the top wall 310. Only then can the storage box 306 be removed by the user for accessing one or more of the samples therein. The user must then return the retainer bar 312 into the inserted position and manipulate the storage rack 300 using the small clip 308 to re-insert the storage rack 300 back into the storage sleeve 314 for movement back into the cryogenic container. As can be readily understood from this description, this multi-step process can take a significant amount of time, particularly for users without significant experience with retrieving samples from these types of storage racks.
Moreover, the conventional design of the sample storage boxes 306 also presents some additional difficulties for users. In this regard, the storage boxes 306 are typically made from a plastic-like or cardboard-like material with openable lids and box ears, but these portions of the storage boxes 306 have a tendency to become brittle and snap off during opening or closing of the storage boxes 306, especially after storage in the cryogenic container at the desired temperature. This problem can negatively impact the reuse of the storage boxes 306, which is typically preferable in many fields. Furthermore, the opening and closing of the storage boxes 306 takes additional time, which can lead to the problems above with prolonged exposure of other samples to higher temperatures before the storage rack 300 can be replaced into the cryogenic container or environment.
For some types of biological and drug samples, thermal-induced degradation can begin after as little as 30 seconds of exposure to room temperatures outside the cryogenic container. Therefore, the significant amount of time needed to retrieve samples and storage boxes 306 from the storage rack 300 and then re-assemble and return the storage rack 300 to cryogenic storage presents a risk that the other samples will be degraded or damaged. Consequently, the conventional designs of storage racks present difficulties for users who need to store and retrieve a plurality of samples in an efficient storage space. While such disadvantages can be avoided by users with significant experience in retrieving the storage racks, it is not always possible to have users with significant experience, which can potentially lead to sample degradation and loss.
It is desirable, therefore, for further improvements in the cryogenic storage rack field and associated systems and methods for cryogenic sample storage, which address these and other deficiencies of known designs.